Noradrenaline, Motivation, Sleep Apnea and Blood Pressure

I've been doing some googling and reading on noradrenaline recently, as I have been prescribed a noradrenaline reuptake inhibitor. The prescription is intended to deal with my general lack of drive and motivation, a feeling most apnea sufferers will have come across before. It appears that noradrenaline helps lift drive and motivation levels - it is closely related to adrenaline. Further research shows that one of the effects that it has in the body is that it contracts blood vessels - helping to increase blood pressure.

There is a function within the lungs which causes blood to be redirected away from oxygen deficient parts of the lung so that it can go to the other (hopefully) oxygen rich parts. This is done by the blood vessels contracting in the oxygen deficient areas of the lungs, and one of the effects of apnea is that the whole lung becomes oxygen deficient, causing all the blood vessels to contract - and pumping against those constrictions is partly what puts the heart under huge strain while undergoing an apnea event. (The other part is that the heart has to pump against those constrictions with a vastly lowered blood oxygen level).

So, I've been putting 2 and 2 together and what I've thought is this: what if the mechanism that the body uses to constrict the blood vessels while in apnea is noradenaline? And what if the body adjusts to large amounts of noradrenaline being released regularly so that it can take it back up more efficiently? And then, when we are awake and there is no need for the noradrenaline to be released, it is being taken up too quickly, and there is therefore less of it free in the body than normal. Could this be the mechanism which causes depression in apnea sufferers? It would explain why the more common approach of prescribing SSRIs (selective serotonin reuptake inhibitors) as opposed to NARIs (noradrenaline reuptake inhibitors) was not all that effective for treating my depression.

Am I deluded or does anyone have any knowledge (and perhaps a link or two) on what meachanisms the body uses to restrict blood flow into the lungs during an apnea attack? Or any information on which neuro=transmitters are responsible for depression in apnea sufferers?

Or perhaps I should stick to computers and leave the tricky stuff to the qualified doctors?

Colin